1. Technical Field
The present disclosure relates to a modulation module, in particular, to a multi-systems integrated modulation module.
2. Description of Related Art
With the continuous development of the wireless communication technology, the mobile communication devices with variety functions (such as smart phone, personal digital assistant (PDA), and so on) have become the tools which people communicate with other people in the life. However, since the communication technology evolves for a long time, the communication device may have many different communication technologies existed therein. Therefore, how the communication technologies successfully operate therebetween in the communication device has become an important issue of wireless communication.
In the short distance communication technology, 2.4 GHz ISM frequency (e.g. industrial, scientific and medical) is the common implementation environment. In the practical implementation environment, two transceiver modulation circuits with different protocols are sited around or in the same device (such as the handheld mobile communication device). For example, the transceiver modulation circuit for transmitting the IEEE 802.11b/g wireless local area network (WLAN) signal and the transceiver modulation circuit for transmitting Bluetooth signal may be sited closely to each other or in the same device. IEEE 802.11b/g WLAN and Bluetooth share the 2.4 GHz frequency. Since the frequencies in which the communication technologies operate are close to each other (the oscillating frequency in range 2.4˜2.48 GHz), it easily causes the transceiver modulation circuits to generate the interference to each other or frequency pulling effect during the modulation procedure, while the distance between the two transceiver modulation circuits is short.
Please refer to FIG. 1. FIG. 1 is a block diagram of a traditional communication device using the Wi-Fi and Bluetooth technology. In FIG. 1, a communication device 1 includes a first modulation module 11, a second modulation module 12, a first communication circuit 13 (which includes a digital-to-analog converting module 131 having an analog-to-digital converter 131a and a digital-to-analog converter 131b and a first communication computing unit 132), a second communication circuit 14 (which includes a digital-to-analog converting module 141 having an analog-to-digital converter 141a and a digital-to-analog converter 141b and a first communication computing unit 142), a switch 15, and an antenna 16. The first modulation module 11 includes a signal amplifier module 111 (which includes low noise amplifier 1111 and a power amplifier 1112), a Wi-Fi modulation circuit 112 (which includes a high frequency oscillator 1121 and a high frequency mixer 1122), a filter module 113 (which includes filter 113a, 113b and a voltage gain amplifier 114). The second modulation module 11 includes a signal amplifier module 121 (which includes a low noise amplifier 1211 and a power amplifier 1212), a Bluetooth modulation circuit 122 (which includes a high frequency oscillator 1221 and a high frequency mixer 1222), filter module 123 (which includes filter 123a, 123b and a voltage gain amplifier 124). The first modulation module 11 is coupled to the first communication circuit 13, and further includes a first receiving terminal 11a and a first transmitting terminal 11b which are coupled to the switch 15. The second modulation module 12 is coupled to the second communication module 12, and further includes a second transceiver terminal 12a coupled to the switch 15. The antenna 16 is switched to connect with the first receiving terminal 11a of the first modulation module 11, the first transmitting terminal 11b of the first modulation module 11, or the second transceiver terminal 12a in the second communication module 12 by the switch 15. The first receiving terminal 11a can receive the Wi-Fi signal or the Bluetooth signal when the switch 15 switches the antenna 16 to connect with the first receiving terminal 11a. The first transmitting terminal 11b can transmit the Wi-Fi signal when the switch 15 switches the antenna 16 to connect with the first transmitting terminal 11b. The second transceiver terminal 12a can transmit the Bluetooth signal when the switch 15 switches the antenna 16 and to connect with the first transceiver terminal 11b. 
In the circuit design, as shown in FIG. 1, the traditional communication device having WiFi and Bluetooth coexisted therein usually has signal amplifier modules 111, 121, filter modules 113, 123, high frequency mixers 1122, 1222, and high frequency oscillator 1121, 1221 respectively. The high frequency mixer 1122 has a high frequency receiving mixer 1122a and a high frequency transmitting mixer 1122b. The high frequency mixer 1222 has a high frequency receiving mixer 1222a and a high frequency transmitting mixer 1222b. It's noted that, the high frequency circuit in the circuit design usually needs the larger circuit area in general, and thus also has the higher cost. In the trend which the user pursues the slim, thin, short, and small product, reducing the circuit area is also an important issue.
On the other hand, the second modulation module 12 for modulating the Bluetooth signal and the first modulation module 11 for modulating the Wi-Fi signal are disposed closely to each other. Since the second modulation module 12 cannot transmit the Wi-Fi signal while the second modulation module 12 transmits the Bluetooth signal, the communication device 1 cannot supply the high task duty operation of Bluetooth and Wi-Fi. In other words, the communication device 1 only can transmit the Bluetooth signal when the switch 15 switches the antenna 16 to connect with the second transceiver terminal 12a. Therefore, when the communication device 1 wants to transmit the Wi-Fi signal at the first transmitting terminal 11b, the communication device 1 cannot transmit the Wi-Fi signal, and must wait until the switch 15 switches the antenna 16 to connect with the first transmitting terminal 11b. Accordingly, the transmission quantity becomes worse, and the high latency may exist. However, for the application program which is sensitive to the latency (e.g. Voice over internet protocol, VoIP), the above operation may causes some problem. Since the traffic of the kind is the voice traffic, the serious delay cannot be tolerated. Moreover, the conflicting problem will cause the poor quality of the voice transmission. To sum up, in the wireless communication technology, it still has to improve the circuit structure, which is disposed in the communication device of multi-protocols used sharing frequency.